Smudging is an indigenous yet worldwide ancient ritual for clearing unwanted or dense/lower vibration energies from any space, home, land etc. as well as around you. The smudge stick, used for ceremonies, is usually a tied bundle of dried White or Blue sage.  The smudge stick is burned as part of the ritual or ceremony. Plants and herbs other than sage are also used for smudging and can include:  Sweet Grass, English Lavender, Palo Santo wood and Cedar to name a few. The smoke emanating from the burning of the sage, for the purpose of clearing, is analogous to the burning of incense in traditional religious ceremonies and is always done with sacred intention and reverence.